Not feeling pregnant!

Needing some positive vibes! We have a beautiful daughter who is 16 months in which we conceived via our first round of IUI. For my second pregnancy, we did 3 rounds of IUI and I finally got my BFP. We went for our first ultrasound at 7 weeks and Baby was only measuring 6 weeks and they could not detect a heartbeat. The Dr. told us it was a 50/50 Chance but, in my heart I knew. We went a week later for another ultrasound and the baby had actually gotten smaller. We decided to try again right away and after our first round after the miscarriage I am now 5 weeks pregnant. We go for our first ultrasound next Wednesday at 6 weeks. I am so nervous and anxious and can’t get excited or “feel pregnant” and I just want to be happy that I’m pregnant but, I’m too worried (which I know isn’t good for the baby but, I can’t help it) hoping we go and Baby has a strong heartbeat and we meet this little one in July. Sorry for the rant just can’t really talk to anyone else other than my husband.